Fuse



Amm E Etmma FUSE A. G. STEINMAYER Original Filed Nov. 30l 1925 Nov. 26, 1929.

VEP-i Patented Nov. 26, 1929 UNITED STATES PATENT OFFICE ALWIN G. STEINMAYER, OE MILWAUKEE, WISCONSIN, lASSIGrNOR, BY MESNE ASSIGN- MENTS, TO LINE MATERIAL COMPANY, OF SOUTH MILWAUKEE, WISCONSIN, A COR- PORATION OF DELAWARE FUSE Original application led November 30, 1925, Serial No. 72,162. Divided and this application filed .Tuly 12, 1926, Serial No. 121,925. Renewed December 26, 1928.

This application is a division of the one filed November 30, 1925, Serial Number 72,162, and has as a general object to simplify and improve the construction of fuses of that type especially designed for interrupting high-voltage circuits upon the occurrence of excessive overloads.

Another object of this invention resides in the provision of an improved fuse construction, wherein the terminal members with whichv the fuse carrying terminal engaging elements are engageable are mounted on the inner ends of the lead-in insulators, whereby but two insulating members are required in l the entire construction.

A further object of this invention resides in the provision of an improved device of the character described, wherein the lead-in insulators and terminal members are fixed upon a'sinole mounting plate which is readily remova ly sec-ured to the rear wall of the fuse housing to facilitate their ready removal as a single unit.

This invention has as a still further object the provision of an improved and simpli- A fied unit in which the fuse element is enclosed throughout its entire length and gases generated by the volatilization of the elements vented outwardly of the housing.

lith the above and other objects in view which will appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein dis closed invention may be made as come within the scope rof the claims.

In the accompanying drawing, I have illustrated one com lete example of the physical embodiment of my invention constructed according to the best mode I have so far devised for the practical application of the principles thereof, and in which:

The single view illustrates a fuse switch construction embodying my invention, the housing being in vertical section and parts of the fuse proper being broken away.

In the drawing, the numeral 5 designates a box or housing having apertures 6 in its rear wall 7 to receive tubular lead-in insulators 8 fixed, as at 9, in a mounting plate 10. The mounting plate is removably secured to the box rear wall by bolts 11 and serves to strengthen the rear wall of the box from which the terminals, to be later described, are supported.

The insulators S have members 12 mounted at their inner ends that carry switch terminal members 13 of the clip type and adapted to receive the terminal engaging elements 14 and 15 of a fuse 16. The terminals 12 have binding screws or other means 17 for electrically connecting the lines 18 of a circuit in which the device is incorporated.

The mounting plate 10 is made of any suitable material and is flanged, as at 19, where it receives the insulators 8, and the inner surfaces of the flanges are recessed or grooved, as at 20, to provide an anchor for the cement or other means 9 employed to secure the insulators in` place. As will be readily apparent, the mounting plate, and with it the insulators and terminals carried thereby, may bebodily removed from the housing by removing the bolts 11, moving the plate 10 from the wall 7 until the flanges 19 disengage the openings 6', shifting the plate longitudinally to align one terminal 13 with its adjacent opening, then withdrawing the aligned terminal from its opening 6 and shifting the mounting longitudinally in an opposite direction to align the other terminal with its opening to permit its withdrawal. vThis construction greatly simplifies the construction of the housing and facilitates repairs or replacement of the parts.

The fuse 16 consists of an elongated open ended tube 21 of suitable insulating material having one end externally threaded, as at 22, and secured within a terminal engaging element 14, the other end of the tube being passed through and extended beyond a second terminal engaging element 15. The threads 22 form means for mounting the element 14 on the tube 21, and the element 15 is fixed thereon by binding bolts 23 arranged to draw the split ends 24 of the element thereabout. The element 14 has a bore 25 in its end which is normally closed by a removable cap 26 threaded on a boss 27 formed on the element, the cap 26 providing means for clamping the upper end 28 of a fuse element 29 in electrical connection with the terminal element. The fuse element 29 preferably has a reduced cross-sectional area 30 adjacent its end 28 and extends through the length of the tube 16 and outwardly thereof with its end 31 folded back along the exterior of the tube and curved to lie within the channel 32 of the enlarged or flanged portion 33 of the element 15 where it is clamped by a-sleeve or collar 34 threaded into flange 33.

The lower end of the tube 21 projecting beyond the terminal element 15 extends through an opening 36 in the bottom 35 of the box to permit the venting of the tube outwardly thereof. A second tube 37 surrounds the extended end of tube 16 and the end portion 31 of the fuse, the second tube being fixed to the sleeve or collar 34 by threads or other means 38 and having its lower end exended beyond the lower end of the first tu e.

The fuse, as a unit, is mounted on a block or other means 39, carried by a Ldoor 40, closing the outer face of the box so that'when the door is opened, the fuse unit is carried therewith to disengage the elements 14 and 15 from the terminals 12 and 13, respectively. The block 39 is connected with the door by a wing nut arrangement 41 so that the door may be opelied without carrying the fuse unit therewit What I claim as my invention is:

1. A fuse construction, comprising a tube of non-conducting material, a fuse element extending through the length ofthe tube and having one end extended therebeyond and bent backwardly along one end portion of the tube, a second tube of greater diameter` than the first and telescoped over the lastmentioned end thereof to enclose the exposed portion'of the fuse element, `and terminal members electrically bridged by the fuse element, said last-mentioned end of the tube and the fold of the fuse element being located inwardly of the outer end of said secondtube, there being an air space between the tubes and the adjacent ends thereof being open to the atmosphere. f

2. A fuse construction, comprising a pair of terminal engaging members, an insulating tube, means mounting one terminal engaging member at one end portion of the tube, means mounting the other member on the tube but spaced from the other end thereof, a fuse element having one end electrically connected with the first-mentioned member and passed through the tube outwardly of its end projecting beyond the other member and being directed along the exterior of the tube, means electrlcally connecting said other end of the element with the other terminal member whereby the fuse element is of approximately hairpin shape, a flange portion on the outer end of said other member, a second tube of greater'diameter than the first and surrounding the projected end thereof and the portion of the fuse element folded along the exterior thereof, and means connecting the second tube with the flange of said other member.

3. Afuse'construction, comprising a pair of terminal engaging members, an insulating tube, means mounting one terminal engaging member at one end portion of the tube, means mounting the other member on the tube but spaced from the other end thereof, a fuse element having one end electrically connected with the first-mentioned member and passing through the tube outwardly of its end projecting beyond the other member and being of greater diameter than the first tube carried by the'sleeve and surrounding the projected `end of the first tube and the portion of the fuse element folded along the exterior there- 4. A fuse construction, comprising a pair of terminal engaging members, an insulating tube, means mounting one terminal engaging member at one end portion of the tube, means mounting the other member on the tube but spaced from the other end thereof, a fuse element having one end electrically connected with the first-mentioned member and passlng .through the tube .outwardly of its end projecting beyond the other member and being directed along the exterior of the tube, whereby the fuse element is of approximately hairpin shape, an internally threaded flange portion on the outer end of said other element, a sleeve member threaded into the flange of said other member and adapted to clamp the adjacent end o f the fuse element between it and said member to electrically connect the fuse element therewith, and a second tube of greater diameter than the first tube carried by said sleeve and surrounding the projected end of the first tube and the portion of the fuse element folded along the exterior thereof, the outer end of said second tube being extended beyond the adjacent end of the first tube and the fold of the fuse element.

5. A fuse construction, comprising a tube of non-conducting material, a 4fuse element extending through the tube and having one end portion bent back along one end portion of the tube, a second tube of greater diameter than the first and telescoped over the lastmentioned end thereof to enclose the exposed portion of the fuse element, there being an air space between the tubes and the adjacent ends thereof bein open to the atmosphere, and terminal mem ers electrically bridged by the fuse element.

6. A fuse construction, comprising a tube of non-conducting material, a fuse element extending through the tube with one end portion thereof projecting beyond one end portion of the tube and directed backwardly 1o therealong, a member having a bore into which the said end portion of the tube is inserted whereby the exposed portion of the fuse element is substantially enclosed, said member and tube having their adjacent portions arranged to provide an air space between the said tube end portion and said member and the adjacent ends thereof being open to the atmosphere, terminal members electrically bridged by the fuse element, and

the fuse having a reduced cross section within the tube.

In testimony whereof I alix my signature.

ALWIN Gr. STEINMAYER. 

